1. Field of the Invention
The embodiments discussed herein are directed to a technology for controlling bandwidths for packets of a plurality of service classes.
2. Description of the Related Art
A policer has been used on a communication network to carry out policing to limit the bandwidth of data traffic that flows through the network. For example, Japanese Laid-open Patent Publication No. 2004-320380 discloses a technology that realizes complete priority control among each of the service classes. This is enabled by adopting a policer with order of priority that takes into account the priority of input traffic, and limiting the bandwidth so that the total of packets corresponding to each of the service classes (for example, a group of network flows being set based on the bandwidth, used and guaranteed for communication) is within a predetermined bandwidth.
A weighted fair queuing (WFQ) shaper has been widely known that, by using a weighted fair queuing (WFQ), limits the flow amount of data traffic while equally allocating the bandwidth with respect to each of the service classes.
With the technology disclosed in Japanese Laid-open Patent Publication No. 2004-320380, although it is possible to police the complete priority control, a bandwidth is not allocated to a service class with low priority. Accordingly, a bandwidth cannot be ensured for the low traffic class. The bandwidth of each service class can be limited while a bandwidth is allocated to the service class with low priority. However, a scheduler and the like provided with a large amount of memories to store queues and a complicated circuit is required at the input side of the traffic. As a result, the scalability is affected significantly.